ThomasFitzalan, 12th Earl of Arundel was born on 13 October 1381.1 He was the son of RichardFitzAlan, 11th Earl of Arundel and ElizabethdeBohun.2,1 He married BeatricedeAviz, daughter of João IdeAviz, Rei de Portugal and InezPerez, on 26 November 1405 at Lambeth, London, England, in the presence of the court. He died on 13 October 1415 at age 34 at Arundel Castle, Arundel, Sussex, England, from dysentery, without legitimate issue.3 He gained the title of 5th Earl of Arundel.4 He was ward for some time to John Holand, Duke of Exeter, by whom he was harshly treated, but managed to escape to the Continent, and joined his uncle, Thomas, the deposed Archbishop of Canterbury, with whom he lived in great poverty.1 Circa 4 July 1399 he landed in England, with Henry, Duke of Lancaster (afterwards King Henry IV).1 He was invested as a Knight, Order of the Bath (K.B.) on 12 October 1399.1 In 1400 he defeated the insurgent nobles, when his former guardian, John Holand, was captured and executed.3 He was invested as a Knight, Order of the Garter (K.G.) in 1400.3 He succeeded to the title of 12th Earl of Arundel [E., c. 1138] in October 1400, after his father's attainder was reversed.1 He fought in the wars against the Welsh between 1401 and 1405.3 He fought in the campaign against the rebellious Archbishop Scrope in 1405.3 He fought in the war against the French in 1411.3 He held the office of Warden of the Cinque Ports on 21 March 1412/13.3 He held the office of High Treasurer on 21 March 1412/13.3 He fought in the taking of Harfleur in 1415.3 According to Gibbs, he was "a capable military man, but savage, revengeful, and self-seeking."3 He has an extensive biographical entry in the Dictionary of National Biography.5